HDAC9 and neoplasm: VPA oral doses of 30 mg/kg daily in combination with the demethylating agent hydralazine, doxorubicin and cyclophosphamide, as neoadjuvant therapy in locally advanced breast cancer patients, was safe and tumor responses appeared higher as compared with historical controls; HDAC inhibition was demonstrated in the peripheral blood of the patients, with a mean plasma concentration of 87.5 μg/ml [11].